Miniaturized valves of this type are defined by an extremely short valve stroke of at most 0.4 mm and/or by a very small fluid space of at most 300 mm3, preferably at most 100 mm3, the fluid space even coming down to 10 mm3 only.
Valves, in particular miniaturized membrane valves working with a rocker to open and close the fluid channels, call for an extremely high manufacturing expense. This is based on the small manufacturing tolerances of the individual components ensuring the short valve stroke. The several components arranged in series each have a range of tolerance which may add up to an overall tolerance that may be almost equal to the valve clearance and the valve stroke. Therefore, valve strokes ranging from 0.2 to 0.3 mm can only be achieved with smallest allowable manufacturing tolerances.
U.S. Pat. No. 4,250,924 shows a valve which, however, does not constitute a miniaturized valve. Here, a sealing element is fastened to a cover underneath each valve seat formed on the cover, the latter delimiting the cavity in upward direction. This fastening of the sealing element is carried out by means of a U-shaped, elastically yielding frame part carrying the sealing element. Depending on the switching condition of one of the sealing elements, the rocker can press against the valve seat and close it. In this process, the rocker is realized as a pure pressing means. The reset for opening the valve seat is effected by the elastically yielding frame which carries the sealing element. One of the two rocker arms is provided with an adjustment screw which allows adjusting the distance of the screw to the sealing element and thus the inclination of the rocker in the initial position.
It is the object of the invention to provide a method of manufacturing a valve, a valve as well as a bank of valves, in which the valve stroke lies within closest limits without involving an extra manufacturing expense.